1. Field of the Invention
This invention relates to a side body structure, and particularly to a technique for enhancing vehicle body rigidity of the periphery of an opening of a front door and the periphery of an opening of a rear door of a vehicle having a front door and a rear door.
2. Description of the Related Art
Generally, a side body of a vehicle is constructed so that a side body inner panel is joined to the inside of the vehicle of a side body outer panel which is an outer plate and a closed sectional structure is formed by these side body outer panel and side body inner panel and rigidity of the vehicle is ensured.
However, in a vehicle such as a passenger vehicle having a front door and a rear door like a four door vehicle, an opening of the front door and an opening of the rear door are formed in a side body, so that there is a disadvantage that an opening area is large and vehicle body rigidity of the side body reduces.
Normally, a rear pillar needs to sufficiently support an input from rear wheels, so that a rear pillar portion is provided with a rear pillar reinforce along a rear edge upper portion of an opening of a rear door between a side body outer panel and a side body inner panel as a reinforcing material and as a result of this, vehicle body rigidity of the periphery of the opening of the rear door is ensured to some extent.
However, the vehicle body rigidity of the whole side body cannot be enhanced by only such a rear pillar reinforce and particularly, a front pillar or a center pillar is narrower than the rear pillar, so that vehicle body rigidity of the periphery of an opening of a front door tends to be low.
Thus, as disclosed in JP-A-9-104358, a side body structure in which a reinforce is interposed between a side body outer panel and a side body inner panel in the periphery of an opening of a front door has been developed.
However, even when the rear pillar reinforce is provided and vehicle body rigidity of the periphery of an opening of a front door is enhanced as shown in the side body structure disclosed in the the publication, vehicle body rigidity of the periphery of an opening of a rear door is still not provided sufficiently.
Particularly, the upper edge of an opening of a rear door is coupled to a roof panel, but the roof panel is a flat plate, so that rigidity is low originally and when vehicle body rigidity of an upper edge portion of the opening of the rear door is low, there is a problem that the upper edge portion of the opening of the rear door tends to be bent and deformed along with the roof panel, for example, at the time of collision of a vehicle. In this case, difficulties in opening and closing the rear door may be caused.